ci(pages): republish the redirector only when it changes

.github/workflows/pages-build-site.yml

@@ -3,12 +3,15 @@ on:
   # The editor now lives at https://edit.chaxus.com (Cloudflare Pages).
   # GitHub Pages publishes ONLY a client-side redirector (redirect/), so old
   # ranuts.github.io/document/* links keep working (path + query preserved).
-  # The app now deploys to Cloudflare Pages from `main`, so GitHub Pages is
-  # main-based too: any push to main republishes the redirector. workflow_dispatch
-  # lets you trigger the first redirector deploy by hand once Cloudflare is live.
+  # GitHub Pages keeps serving the last published artifact, so the redirector
+  # only needs republishing when it changes; every other push to main used to
+  # redeploy the same two files. workflow_dispatch republishes by hand.
   push:
     branches:
       - main
+    paths:
+      - "redirect/**"
+      - ".github/workflows/pages-build-site.yml"
   workflow_dispatch:
 
 # Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages

docs/explorations/2026-11-02-pages-redirector-paths.md

@@ -0,0 +1,14 @@
+# GitHub Pages 跳转页不再每次推送都重新发布
+
+`pages-build-site.yml` 只负责把 `redirect/`（`index.html` + `404.html`）发布到 GitHub Pages，
+让旧的 `ranuts.github.io/document/*` 链接带着路径和参数跳到 edit.chaxus.com。
+
+它原来对 main 的每一次推送都跑一遍，于是仓库的 Deployments 页面堆了上百条 `github-pages` 记录：
+2026-08 到 2026-11 共 100 次，而 `redirect/` 自 2026-07-05 上线后只改过一次。
+GitHub Pages 会一直托管最后一次发布的产物，重复发布同样两个文件没有任何作用。
+
+改动：`push` 触发加 `paths`，只有 `redirect/**` 或这个 workflow 文件本身变化时才发布，保留 `workflow_dispatch` 手动发布。
+**不能关掉 GitHub Pages**：关掉之后旧链接就没有跳转页了。
+
+验证：2026-11-02 `curl https://ranuts.github.io/document/` 返回的就是当前 `redirect/index.html`，
+说明最后一次发布的产物仍在托管。`workflow-contract.test.ts` 68 条通过。